Winter Bugs


With imminent frosty mornings and dark afternoons in the near future comes a well expected rise in respiratory tract illnesses. And like always the top of the list are Cold and flu.

Due to cold weather most people tend to stay indoors, don’t open house/car windows and get less exercise and fresh air. All these are ideal for cold and flu bugs to spread from one person to others. Although both cold and flu are airborne diseases but cold has been found to spread more from contaminated surfaces. Flu on the other hand is very contagious due to high degree of airborne characteristics. This is why Flu may lead to endemics and even pandemics.

Imagine travelling via tube/train/tram or bus during rush hours with several strangers during a peak season of such contagious viral illness. Public awareness of hygiene is as important as prophylaxis such as vaccination.

There is no vaccination available against cold. Thankfully, the common cold is a self-remitting illness and doesn’t pose much health threat unless the sufferer is from high risk group. Elderly, the very young, immunocompromised, frail and people with neurodevelopmental illness and long term health condition (involving heart, lung, liver, kidneys, blood disorder), however, are still at risk of developing complications from a common cold. For healthy population a symptomatic treatment is all that is required for common cold.

Influenza ( also known as flu), on the other hand, is far more serious due to its super contagious nature and worse health outcomes, especially in high risk group as described above. Pregnant women; residents of nursing homes and healthcare staff is also added to the list of at risk group when considering protection against flu. Since 2014 a Quadrivalent vaccine has been available. This protects against two well-known Type A influenza Viruses and both subtypes of Type B influenza viruses. The best time of vaccination against flu is before the end of October. Children between the age of 2-17 years will receive Live attenuated influenza vaccine (LAIV) for year 2019-2020 unless contraindicated. For infants of age 6months-23 months and those who are 2y-17 years but can’t receive LAIV will be offered egg-grown quadrivalent influenza vaccine (QIVe). People aged 18-64 can receive Quadrivalent vaccine that is either recombinant or egg-grown. Those who are above 65Y old adjuvant Trivalent Influenza Vaccine has been approved but can also receive recombinant quadrivalent vaccine.

WINTER BUGS: LET’S EXPLORE

Cold: Also known as common Cold, Coryza

  • A spontaneously remitting viral infection

  • Self-limiting

  • Contagious (although airborne but mostly spread via touching contaminated surfaces)

  • Causative Virus has more than 200 subtypes

  • Broadly classified into

  1. Rhinovirus (causes infection in winter mostly)

  2. Coronavirus ( Culprit for March-April infections as well as some winter ones)

  • Symptoms as below:

  1. Runny/stuffy nose

  2. Sneezing

  3. Sore throat

  4. Fever

  5. Malaise

  6. Halitosis (Bad breath)

  • Diagnosed clinically via symtpoms

  • Managed/treated symptomatically

  • Found to be linked to more lower respiratory complications

  • Vaccination not available due to variability of antigenic properties of both Rhino and Crono Virus

  • Complications are seen in at risk group such as young children born prematurely, elderly people, immunocompromised population, smokers, those with significant co-morbidity involving cardiac, renal, lung, liver or neuromuscular disease

  • Complications involve

  1. Sinusitis

  2. Otitis media

  3. Croup in young children

  4. Chest infection (Bronchitis, Bronchiolitis, Pneumonia, exacerbation of Asthma/COPD)

References: NICE CKS Common Cold 2016, Patient.info (medical professional). Simancas-Racines D et al. database syst rev.2017 (ncbi.nlm.nih.gov)

Influenza: Also known as flu

  • An upper respiratory tract infection caused by Influenza virus

  • Contagious (main method of spread is airborne but is also spread via contaminated surfaces)

  • Broadly has four types of causative viruses

  • Type A influenza Virus

  • Mainly affects animals but also affects humans

  • This virus changes antigenic properties very rapidly, constantly evolving

  • Type A is main cause of flu epidemics and pandemics

  • Any influenza type A virus is described by combining two types of surface protein

  • These surface proteins are H (Hemagglutinin) and N (Neuroaminidase)

  • H type surface protein has further 18 subtypes

  • N type surface protein has further 11 subtypes

  • You will find an influenza type A virus named as H1N1, H3N2 to understand the surface protein in question

  • Antiviral drugs used for treatments and post exposure prophylaxis such as Oseltamivir are Neuroaminidase inhibitors

  • Currently vaccine is only available against H1N1 and H3N2

  • Type B influenza Virus

  • Mainly affects humans and also found in infected seals

  • WHO currently classifies into two subtypes (Type B/Yamagata and Type B/Victoria)

  • Previously trivalent flu vaccine would only provide protection against one of its subtypes

  • Current Quadrivalent vaccine (Since 2014) provides protection against both subtypes

  • Linked to epidemics but not as much as Type A influenza virus

  • Type C influenza Virus

  • This causes mild form of illness

  • It is detected less frequently

  • It does not pose much public health threat

  • No vaccines have been developed against this type

  • Type D influenza Virus

  • This only affects cattle

  • Symptoms of influenza:

  • Sudden onset of fever

  • Cough (usually dry)

  • Severe malaise ( generally feeling unwell)

  • Muscle and joint pain

  • Sore throat

  • Runny nose/stuffiness (Sneezing isn’t as prominent as in Cold)

  • Fatigue

  • Anorexia

  • Headache

  • Abdominal symptoms (Diarrhoea , nausea, vomiting)

  • Diagnosis:

  • May perform a nasopharyngeal swab

  • Treatment

  • Patients not from high risk managed symptomatically

  • Following patients are classed as high risk group

  • Pregnant women

  • Children under the age of 5

  • Elderly

  • Immunocompromised

  • Patients with long term conditions involving heart, liver, lungs, kidneys, haematology and neurodevelopmental aspects.

  • Health workers

  • Management

  • Prevention is the best weapon against influenza

  • Vaccination needs to be repeated annually due to gradual reduction in immunity over time

  • All high risk group patients should be vaccinated

  • Injectable vaccines are either inactivated or recombinant (egg free)

  • Nasal spray vaccine contains live attenuated (less virulent ) virus

  • Post exposure treatment

  • Patients not from high risk category managed symptomatically

  • Patients known to be from high risk group and have been confirmed or suspected to have influenza infection should be started with antiviral treatment ; Oseltamivir (oral)/Zanamivir (nasal) as soon as possible.

  • A minimum of 5 days’ treatment with the above antivirals is recommended

  • All current influenza viruses are resistant to Adamantane antivirals ( eg Amantadine)

  • Note: Rx for Oseltamivir/Zanamivir must be endorsed SLS as the chemist will refuse to dispense without this

  • Complications

  • Respiratory complications involve acute Bronchitis, Secondary bacterial pneumonia, Asthma/COPD exacerbation, Pulmonary aspergillosis and sinusitis

  • Non- respiratory complications involve febrile convulsions, Otitis media, TSD, Myositis, Myocarditis, Encephalitis, Reye’s syndrome, Heart failure

  • Risk of Complications which leads to hospitalisation and death is higher among

  • Those over the age of 65

  • Very young children

  • Those who have current long term conditions as described above

References: BNF, nice.org.uk, WHO.int (accessed 01/10/2019), Centre of disease control and prevention.gov

Reference: england.nhs.uk (Public health Published March 2019)


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